High-resolution Fourier transform infrared spectra of the CH3 n3and CH2D n4 bands

The spectrum of the n3 band CH3 was observed in the 2800-3100 cm-1 region with a Fourier transform infrared spectrometer. The 76 observed lines were analyzed together with the previous difference frequency data to determine the molecular constants including sextic centrifugal distortion constants and the A1 - A2 splitting constant in the ground state. The n4 band (out-of-plane vibrational mode) of CH2D was observed in the 550-700 cm-1 region by a discharge in a mixture of CH2DI and Ar. The molecular constants in both the ground and the n4 states of this radical have been determined for the first time.